package com.example.birdfriends.utils.verifyCode;

import javax.imageio.ImageIO;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Random;

public class VerificationCode {
    private final int width = 100;  // 验证码图片宽度
    private final int height = 40;  // 验证码图片的高度
    private final String[] fontNames = { "宋体", "楷体", "隶书", "微软雅黑" };
    private final Color bgColor = new Color(255, 255, 255);  // 验证码图片的背景颜色
    private final Random random = new Random();
    private String text;  // 记录随机生成的验证码

    private Color randomColor(){
        int red = random.nextInt(150);
        int green = random.nextInt(150);
        int blue = random.nextInt(150);
        return new Color(red, green, blue);
    }

    // 获取随机字体
    private Font randomFont(){
        String name = fontNames[random.nextInt(fontNames.length)];
        int style = random.nextInt(4);
        int size = random.nextInt(5) + 24;
        return new Font(name, style, size);
    }

    // 获取一个随机字符
    private char randomChar(){
        String codes = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
        return codes.charAt(random.nextInt(codes.length()));
    }

    // 创建一个空白的BufferImage对象
    private BufferedImage createImage(){
        BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
        Graphics2D g2 = (Graphics2D) image.getGraphics();
        g2.setColor(bgColor);
        g2.fillRect(0, 0, width, height);
        return image;
    }

    public BufferedImage getImage(){
        BufferedImage image = createImage();
        Graphics2D g2 = (Graphics2D) image.getGraphics();
        StringBuffer sb =  new StringBuffer();
        for(int i = 0; i < 4; i++){
            String s = randomChar() + "";
            sb.append(s);
            g2.setColor(randomColor());
            g2.setFont(randomFont());
            float x = i * width * 1.0f / 4;
            g2.drawString(s, x, height - 8);
        }
        this.text = sb.toString();
        drawLine(image);
        return image;
    }

    private void drawLine(BufferedImage image){
        Graphics2D g2 = (Graphics2D) image.getGraphics();
        int num = 5;
        for(int i = 0; i < num; i++){
            int x1 = random.nextInt(width);
            int y1 = random.nextInt(height);
            int x2 = random.nextInt(width);
            int y2 = random.nextInt(height);
            g2.setColor(randomColor());
            g2.setStroke(new BasicStroke(1.5f));
            g2.drawLine(x1, y1, x2, y2);
        }
    }

    public String getText(){
        return text;
    }

    public static void output(BufferedImage image, OutputStream out) throws IOException{
        ImageIO.write(image, "JPEG", out);
    }
}
